http://blogs.esa.int/mex/2012/08/05/time-delay-between-mars-and-earth/ “Mars is so far away in fact that it takes radio signals quite a long time to get from the spacecraft back to Earth. During Curiosity EDL, this delay will be 13 minutes, 48 seconds, about mid-way between the minimum delay of around 4 minutes and the maximum of around 24 minutes”.

When people settle on Mars, there could be strategies to reduce the appearance of the time delay for the Internet. Different web pages could be present to servers on Mars so that people there could get immediate access to them. This could include their e-mails, selected, popular news articles from each major story, the favorite websites of each settler, and the first 24 minutes of the most popular streaming movies. Stuff like that.